Ghrelin Levels After Weight Loss Surgery

More and more often, people who are “morbidly obese,” 100 pounds or more overweight, are resorting to surgery to lose weight. The American Society for Bariatric Surgery estimates that 62,500 weight-loss operations will be performed in the United States this year. There were 40,000 in 2000, and 20,000 in 1995.

Gastric Bypass

The most commonly performed operation is the gastric bypass, in which much of the stomach is sealed off, leaving just a small pouch that will hold only a few tablespoons of food. The small intestine is also re-routed, so that only part of it is available to absorb nutrients. People can eat only tiny meals, and their absorption is also limited. Within two years of the surgery, many have lost 100 pounds.

But many surgeons say the operations work much better than they would predict, judging from just the physical changes made to the stomach and intestine. Many patients lose their appetites to a greater degree than doctors would expect.

Gastric Bypass Reduces Appetite Hormone?

Dr. Walter Pories, a professor of surgery and biochemistry at East Carolina University in Greenville, N.C., and president-elect of the society for bariatric surgery, said he and other doctors had long suspected that the gastric bypass operation might be decreasing the levels of some hormone made in the gut – they had no idea which hormone – that was affecting appetite, blood sugar and weight.

Ghrelin Levels Fall After Weight Loss Surgery

Ghrelin might be the mystery hormone. When Cummings and his colleagues measured it in people who had had the surgery from nine months to 31 months earlier, they found ghrelin levels to be one-third or less of the lowest levels found in normal weight or overweight people who had not had the surgery. And the surgical patients did not have the spikes seen before and after meals in the other people.